Thanks for that good info about the coolant Ken W.
I guess I haven't kept up and/or shopped for coolant in quite a while.
So here's a question then, if I have the blue stuff in my system now, is it safe to top up or add some of the prestone to it?

I've heard that the pink stuff VW sells and puts in its new cars these days shouldn't be mixed with the blue, and that it will congeal and glob.